Previous research in this Laboratory has examined personality profiles of cultures obtained by averaging traits assessed in samples of college students and adults. We have extended this line of research by examining ratings of 12 to 17 years old in 24 cultures. Observer ratings of adolescents were obtained using the NEO Personality Inventory-3 (NEO-PI-3), a more readable version of the Revised NEO Personality Inventory (NEO-PI-R), which showed good psychometric properties across cultures. Aggregate scores were generalizable across age and gender and showed convergence with culture-level scores from previous studies of self-reports and observer ratings of adults. Non-Western cultures tend to score slightly lower on a dimension related to Extraversion. Further, aggregate scores of adolescent ratings were unrelated to national character stereotypes, consistent with previous research that challenge the accuracy of these widely shared beliefs. Perceptions of aging influence societal behaviors and expectations toward older people as well as older adults well-being and coping with the aging process. In a 26 cultures study we examined perceptions of age-related changes in physical, cognitive, social, and emotional areas of functioning and rated societal views of aging within each culture. There was widespread cross-cultural consensus regarding the expected direction of aging trajectories with (a) perceived declines in physical attractiveness, the ability to perform everyday tasks, and new learning;(b) perceived increases in wisdom, knowledge, and received respect;and (c) perceived stability in family authority and life satisfaction. Cross-cultural variations in aging perceptions were associated with culture-level indicators of population aging, education levels, values, and national character stereotypes. These associations were stronger for societal views on aging and perceptions of social and emotional changes than for perceptions of physical and cognitive changes. A consideration of culture-level variables also suggested that previously reported differences in aging perceptions between Asian and Western countries may be related to differences in population structure. The multinational study includes assessments of personality stereotypes of age groups and genders as well as nations. Preliminary analyses suggest that (a) age is more important that gender or culture in determining perceptions of a group;(b) age stereotypes are generally accurate in the direction of age changes, but not the timing;and (c) the stereotype of the typical culture member can be approximated by summing across age- and gender-specific national stereotypes. These analyses will provide important new information on the conditions under which stereotypes are, or are not, accurate. In a further study, we examined the differential reliability and validity of facet scales from the NEO Inventories using cross-cultural, longitudinal, and family based study (N = 34,108). We evaluated the extent to which (a) psychometric properties of facet scales are generalizable across ages, cultures, and methods of measurement, and, (b) validity criteria are associated with different forms of reliability. Composite estimates of facet scale stability, heritability, and cross-observer validity were broadly generalizable. Two estimates of retest reliability were independent predictors of the three validity criteria;none of three estimates of internal consistency was. Available evidence suggests the same pattern of results for other personality inventories. Internal consistency of scales can be useful as a check on data quality but appears to be of limited utility for evaluating the potential validity of developed scales, and it should not be used as a substitute for retest reliability.